v0.2.0

Added

• Auto-fallback chain — when hey runs in auto mode and the first backend fails (rate limit, auth, network), it surfaces a short inline notice and transparently retries with the next available backend. Chain is claude → codex → openrouter, filtered by what's installed.
• Codex rate-limit detection — hey now inspects Codex stdout/stderr/output-file for rate-limit and quota markers and produces a friendly "codex is rate-limited — try 'hey claude ...' or 'hey openrouter ...' instead" instead of a raw subprocess error.
• Codex auth-error detection — "not authenticated" errors from codex exec now produce a clear "run 'codex login' first" message.

Fixed

• hey: error prefix (was still showing the old ait: project name)
• Codex backend swallowing stdout — useful diagnostic info is now aggregated from stdout, stderr, and the -o output file before deciding what error to show.